The present invention concerns a cylindrical surge arrester with a porcelain housing having safety shields surrounding the housing and at one end at least one blow-out aperture that is directed parallel to the cylinder axis of the surge arrester at the surface of the porcelain housing.
Such a surge attester is known, for example, from German patent DE-OS 2, 655,557. The surge arrester described therein has a porcelain housing with surrounding safety shields, all of which have the same outside diameter. In the event of a high short-circuit current, hot gas is blown over the safety shields and the surface of the surge arrester parallel to its axis from a blow-out aperture. The hot gas is blown out at a high pressure, and the flow of gas can break away the porcelain from the safety shields.
German patent DE-A 3,417,648 discloses a surge arrester that has a porcelain housing surrounded with safety shields. In this device the safety shield closest to the blow-out aperture has a smaller diameter than the safety shield that follows it.